Method of fabricating reflection type liquid crystal display

ABSTRACT

A liquid crystal display device includes (a) a first substrate, (b) a second substrate spaced away from and facing the first substrate, (c) a liquid crystal layer sandwiched between the first and second substrates, (d) a transistor formed on the first substrate, (e) a wiring layer formed on the first substrate and electrically connected to the transistor, (f) a reflection electrode formed on the first substrate, an external incident light being reflected at the reflection electrode towards a viewer, and (g) a compensation layer formed directly on the wiring layer. The reflection electrode does not cover the wiring layer therewith, and the compensation layer has almost the same height as a height of the reflection electrode, the height being measured from a surface of the first substrate.

This application is a division of co-pending application Ser. No.11/030,188, filed on Jan. 7, 2005. Ser. No. 11/030,188 is a division ofco-pending application Ser. No. 09/987,013, filed on Nov. 13, 2001,which claims priority to prior Japanese Application No. 2000-343714,filed on Nov. 10, 2000, the entire contents of which are herebyincorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a liquid crystal display device and a method offabricating the same, and more particularly to a reflection type liquidcrystal display device in which an external incident light is reflectedtowards a viewer such that the reflected light acts as a light source,and a method of fabricating the same.

2. Description of the Related Art

As one of liquid crystal display devices, there is known a reflectiontype liquid crystal display device. The reflection type liquid crystaldisplay device includes a reflection layer at which an external incidentlight is reflected towards a viewer, and hence, is not necessary toinclude a back light source unlike a transmission type liquid crystaldisplay device which has to include a back light source as a lightsource.

FIG. 1 is partial cross-sectional view of a conventional reflection typeliquid crystal display device.

As illustrated in FIG. 1, the reflection type liquid crystal displaydevice 1 is comprised of a lower substrate 2, an opposing substrate 4spaced away from and facing the lower substrate 2, and a liquid crystallayer 3 sandwiched between the lower and opposing substrates 2 and 4.

The lower substrate 2 includes an electrically insulating substrate 2 a,a semiconductor device 5, a drain wiring 6, projections 7, anelectrically insulating layer 8, and a reflection electrode 9. Thesemiconductor device 5 and drain wiring 6 are formed on the substrate 2a, and the projections 7 are formed on the substrate 2 a in a pattern.The electrically insulating layer 8 covers the semiconductor device 5,the drain wiring 6 and the projections 7 therewith. The reflectionelectrode 9 is formed directly on the electrically insulating layer 8.

The opposing substrate 4 includes an electrically insulating substrate 4a, and a transparent electrode 4 b formed on the substrate 4 a andfacing the liquid crystal layer 3.

The electrically insulating layer 8 is composed of organic material,inorganic material or a combination of organic and inorganic materials.The electrically insulating layer 8 formed on the drain wiring 6 acts asa passivation layer for protecting the semiconductor device 5.

The conventional reflection type liquid crystal display device 1 isaccompanied with a problem as follows.

Since the drain wiring 6 is covered only with the thin electricallyinsulating layer 8, a light reflected at the drain wiring 6 isunavoidably yellowish in color, resulting in harmful influence to thedisplay characteristic of the reflection type liquid crystal displaydevice 1.

FIG. 2 illustrates how lights are reflected in the reflection typeliquid crystal display device 1.

As illustrated in FIG. 2, incident lights Lia and Lib pass through theopposing substrate 4 and the liquid crystal layer 3, reach the lowersubstrate 2, and are reflected at the lower substrate 2. The reflectedlights Lra and Lrb pass through the liquid crystal layer 3 again, andleave the opposing substrate 4.

Since the drain wiring 6 is covered only with the thin insulating layer8 composed of metal, a space between the drain wiring 6 and the opposingsubstrate 4 is greater than a space between the reflection electrode 9and the opposing substrate 4. As a result, the light Lrb reflected atthe drain wiring 6 would have a greater birefringence rate (Δn×d) thanthat of the light Lra reflected at the reflection electrode 9, andaccordingly, the reflected light Lrb would be yellowish. This causes aproblem that when the liquid crystal display device displays a whiteimage, the white image would be yellowish.

Japanese Unexamined Patent Publication No. 6-75238 has suggested aliquid crystal display device including a first transparent substrate, asecond transparent substrate facing the first transparent substrate, aliquid crystal layer sandwiched between the first and second transparentsubstrates, a plurality of reflections electrodes formed on the firsttransparent substrate for reflecting an incident light having passedthrough the second transparent substrate, voltage-applying electrodeswhich apply a voltage to each of the reflection electrodes, and alight-permeable common electrode formed almost all over the secondelectrode. The reflection electrodes cover the first transparentsubstrate therewith except portions through which the reflectionelectrodes are connected to each other above the voltage-applyingelectrodes, and are formed on an electrically insulating film having aplurality of projections, only in an area in which the reflectionelectrodes are formed such that the reflection electrodes do not overlapthe voltage-applying electrodes.

Japanese Unexamined Patent Publication No. 2001-201742 having beenpublished on Jul. 27, 2001 has suggested a liquid crystal display deviceincluding a first transparent substrate, a transparent electrode formedon the first transparent substrate, a second substrate, an electricallyinsulating film formed on the second substrate and having a wavysurface, a reflection electrode formed on the electrically insulatingfilm and having a surface reflecting the wavy surface of theelectrically insulating film, and a liquid crystal layer sandwichedbetween the first and second substrates. The electrically insulatingfilm is comprised of a first insulating layer having a plurality ofnon-uniformly arranged recessed portions defined by raised portionssurrounding the recessed portions, and a second insulating layerentirely covering the first insulating layer therewith.

The above-mentioned problem remains unsolved even in the above-mentionedPublications.

It should be noted that Japanese Unexamined Patent Publication No.2001-201742 constitutes statutory prior art to the present invention.The applicant refers to the Publication No. 2001-201742 only for thepurpose of explanation of the present invention, and the reference tothe Publication No. 2001-201742 does not mean that the applicant admitsthat the Publication No. 2001-201742 constitutes statutory prior art tothe present invention.

SUMMARY OF THE INVENTION

In view of the above-mentioned problem in the conventional liquidcrystal display devices, it is an object of the present invention toprovide a liquid crystal display device which is capable of preventing areflected light from becoming yellowish to thereby prevent a white imagedisplayed in a liquid crystal display device from becoming yellowish. Itis also an object of the present invention to provide a method offabricating such a liquid crystal display device.

In one aspect of the present invention, there is provided a liquidcrystal display device including (a) a first substrate, (b) a secondsubstrate spaced away from and facing the first substrate, (c) a liquidcrystal layer sandwiched between the first and second substrates, (d) atransistor formed on the first substrate, (e) a wiring layer formed onthe first substrate and electrically connected to the transistor, (f) areflection electrode formed on the first substrate, an external incidentlight being reflected at the reflection electrode towards a viewer, and(g) a compensation layer formed directly on the wiring layer, thereflection electrode not overlapping the wiring layer, the compensationlayer having almost the same height as a height of the reflectionelectrode, the height being measured from a surface of the firstsubstrate.

The liquid crystal display device may further include an electricallyinsulating film having a wavy surface, and wherein the reflectionelectrode is formed on the electrically insulating film and has asurface reflecting the wavy surface of the electrically insulating film.

For instance, the electrically insulating film may be comprised of aprojection formed on the first substrate, and an insulating layercovering the projection therewith.

It is preferable that the electrically insulating film is formed also onthe wiring layer as the compensation layer in which the projection isformed on the wiring layer.

It is preferable that the electrically insulating film formed on thewiring layer has a height greater than a height of a lowest portion ofthe wavy surface of the electrically insulating film.

For instance, the compensation layer is comprised of a projection formedon the wiring layer, and an insulating layer covering the projectiontherewith.

It is preferable that the reflection electrode and the wiring layer donot overlap each other.

It is preferable that the reflection electrode has ends located aboveand in alignment with opposite ends of the wiring layer.

The liquid crystal display device may further include thin filmtransistors each acting as a switching device and each applied to eachof pixels.

It is preferable that the projection is comprised of a first projectiondefining a rectangular frame, and a second projection defining aplurality of linear projections each extending in different directionsfrom one another within the rectangular frame.

It is preferable that the first projection is formed on the wiringlayer.

It is preferable that the first projection has a greater width than awidth of the linear projections.

In another aspect of the present invention, there is provided a methodof fabricating a liquid crystal display device including a firstsubstrate, a second substrate spaced away from and facing the firstsubstrate, a liquid crystal layer sandwiched between the first andsecond substrates, and a reflection electrode formed on the firstsubstrate, an external incident light being reflected at the reflectionelectrode towards a viewer, the method including the steps of (a)forming a switching device and a wiring layer on the first substrate,the wiring layer being electrically connected to the switching device,(b) forming a first projection on the wiring layer and secondprojections on the first substrate, (c) covering the first and secondprojections with an electrically insulating layer, (d) forming anelectrically conductive film over the electrically insulating layer, and(e) patterning the electrically conductive film such that theelectrically conductive film does not overlap the wiring layer.

For instance, the step (e) may include the steps of (e1) forming aphotoresist layer over the electrically conductive film, (e2) forming ahole throughout the photoresist layer above the wiring layer, the holereaching the electrically conductive film, and (e3) etching theelectrically conductive film such that an etched portion of theelectrically conductive film has a length greater than a width of thehole.

It is preferable that the first projection and the electricallyinsulating layer are formed to have almost the same height as a heightof the second projections, the electrically insulating layer and theelectrically conductive film.

It is preferable that the electrically insulating layer is formed tohave a wavy surface, and the electrically conductive film is formed tohave a surface reflecting the wavy surface of the electricallyinsulating layer.

It is preferable that the electrically conductive film is formed to haveends located above and in alignment with opposite ends of the wiringlayer.

It is preferable that the first projection defines a rectangular frame,and the second projections define a plurality of linear projections eachextending in different directions from one another within therectangular frame.

It is preferable that the first projection is formed to have a greaterwidth than a width of the linear projections.

The advantages obtained by the aforementioned present invention will bedescribed hereinbelow.

In accordance with the present invention, the compensation layer formedon the wiring layer is designed to have almost the same height as aheight of the reflection electrode. Herein, the height is measured froma surface of the first substrate. Hence, a space between the reflectionelectrode and the second substrate is almost equal to a space betweenthe compensation layer and the second substrate. This ensures that alight reflected at the compensation layer is prevented from beingyellowish, further ensuring a white image displayed in a screen of theliquid crystal display device is prevented from being yellowish.

The above and other objects and advantageous features of the presentinvention will be made apparent from the following description made withreference to the accompanying drawings, in which like referencecharacters designate the same or similar parts throughout the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial cross-sectional view of the conventional liquidcrystal display device.

FIG. 2 illustrates how a light is reflected in the conventional liquidcrystal display device illustrated in FIG. 1.

FIG. 3 is a partial cross-sectional view of the liquid crystal displaydevice in accordance with the first embodiment of the present invention.

FIG. 4 is a plan view of a pattern of projection within a pixel in theliquid crystal display illustrated in FIG. 3.

FIG. 5 illustrates how a light is reflected in the liquid crystaldisplay device illustrated in FIG. 3.

FIG. 6A is a cross-sectional view showing a positional relation betweenthe drain wiring and the reflection electrode in the liquid crystaldisplay illustrated in FIG. 3.

FIG. 6B is a cross-sectional view showing another positional relationbetween the drain wiring and the reflection electrode in the liquidcrystal display illustrated in FIG. 3.

FIGS. 7A to 7D are cross-sectional views showing steps to be carried outin the method of fabricating the liquid crystal display illustrated inFIG. 3.

FIGS. 8A and 8B are cross-sectional views showing steps to be carriedout for forming the reflection electrode.

FIGS. 9A and 9B are cross-sectional views showing another steps to becarried out for forming the reflection electrode.

FIG. 10A is a graph showing a relation between a width of a mask patternand a width of the resultant projection.

FIG. 10B is a graph showing another relation between a width of a maskpattern and a width of the resultant projection.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 3 is a partial cross-sectional view of the liquid crystal displaydevice in accordance with the first embodiment of the present invention.

As illustrated in FIG. 3, the liquid crystal display device 10 iscomprised of a lower substrate 11, an opposing substrate 13 spaced awayfrom and facing the lower substrate 11, and a liquid crystal layer 12sandwiched between the lower and opposing substrates 11 and 13.

The liquid crystal display device 10 is designed to include a thin filmtransistor (TFT) as a switching device in each of pixels. That is, theliquid crystal display device 10 is an active matrix type liquid crystaldisplay device.

The lower substrate 11 includes a first electrically insulatingsubstrate 14, a thin film transistor 15, a drain wiring 16, acompensation layer formed on the drain wiring 16 and comprised of afirst projection 17 a and a later mentioned electrically insulatinglayer 18 covering the first projection 17 a therewith, a plurality ofsecond projections 17 b formed on the first electrically insulatingsubstrate 14, an electrically insulating layer 18 covering the firstelectrically insulating substrate 14, the thin film transistor 15, thefirst projection 17 a and the second projections 17 b therewith, and areflection electrode 19 formed on the electrically insulating layer 18such that the reflection electrode 19 does not overlap the wiring layer16 therewith.

The thin film transistor 15 and the drain wiring 16 are formed on thefirst substrate 14, and the second projections 17 b are formed on thefirst substrate 14 in a pattern as mentioned later. The electricallyinsulating layer 18 is formed with a contact hole 18 a therethroughreaching a source electrode of the thin film transistor 15.

The first projection 17 a formed on the drain wiring 16 is covered onlywith the electrically insulating layer 18, whereas the secondprojections 17 b are covered with both the electrically insulating layer18 and the reflection electrode 19.

The reflection electrode 19 is electrically connected to a source ordrain electrode (not illustrated), and act as a reflector and a pixelelectrode. An incident light passing through the opposing electrode 13is reflected at the reflection electrode 19 towards a viewer. That is,the thus reflected light acts as a light source.

The opposing substrate 13 includes a second electrically insulatingsubstrate 20, and a transparent electrode 21 formed on the secondsubstrate 20 and facing the liquid crystal layer 12.

A light enters the second substrate 13, passes through the liquidcrystal layer 12, reaches the lower substrate 11, is reflected at thelower substrate 11, passes through the liquid crystal layer 12 again,and leaves the liquid crystal display device 10 through the secondsubstrate 20.

FIG. 4 is a plan view of a pattern of the first projection 17 a and thesecond projections 17 b.

As illustrated in FIG. 4, the first projection 17 a defines arectangular frame associated with a pixel, and the second projections 17b is comprised of a plurality of linear projections each extending indifferent directions from one another within the rectangular framedefined by the first projection 17 a.

Since the first and second projections 17 a and 17 b are formed in sucha pattern as illustrated in FIG. 4, the electrically insulating film 18covering the first and second projections 17 a and 17 b has a wavysurface reflecting the first and second projections 17 a and 17 b, andfurther, the reflection electrode 19 has a wavy surface reflecting thewavy surface of the electrically insulating film 18.

The first projection 17 a is designed to have a width greater than awidth of the second projections 17 b such that the first projection 17 acan entirely cover the drain wiring 16 therewith. The electricallyinsulating film 18 covers both the first and second projections 17 a and17 b therewith.

The electrically insulating film 18 is composed of organic material,inorganic material or a combination of organic and inorganic materials,and is equal to or greater in height than the second projections 17 b.

Above the drain wiring 16 are formed the first projection 17 a and theelectrically insulating film 18. As illustrated in FIG. 3, theelectrically insulating film 18 has a rounded summit, and has a heightgreater than a height of a lowest portion of the wavy surface of theelectrically insulating film 18.

As illustrated in FIG. 5, the compensation layer comprised of the firstprojection 17 a and the electrically insulating layer 18 has almost thesame height as a height of the reflection electrode 19, wherein a heightis measured from a surface of the first substrate 14 a. Accordingly, athickness of the liquid crystal layer 12 between the reflectionelectrode 19 and the opposing substrate 13 is almost equal to athickness of the liquid crystal layer 12 between the compensation layerand the opposing substrate 13.

FIG. 5 shows how a light is reflected in the liquid crystal displaydevice 10.

As illustrated in FIG. 5, a first incident light Lia enters the opposingsubstrate 13, passes through the liquid crystal layer 12, reaches thelower substrate 11, is reflected at the reflection electrode 19, passesthe liquid crystal layer 12 again, and leaves the opposing electrode 13as a reflected light Lra. A second incident light Lib enters theopposing substrate 13, passes through the liquid crystal layer 12,reaches the lower substrate 11, is reflected at the drain wiring 16,passes the liquid crystal layer 12 again, and leaves the opposingelectrode 13 as a reflected light Lrb.

The first incident light Lia has a birefringence rate Δn×Da wherein Δnindicates an index of refraction of the liquid crystal layer 12 and Daindicates a gap between the reflection electrode 19 and the opposingelectrode 13, and the second incident light Lib has a birefringence rateΔn×Db wherein Δn indicates an index of refraction of the liquid crystallayer 12 and Db indicates a gap between the compensation layer and theopposing electrode 13.

As mentioned earlier, the compensation layer has almost the same heightas a height of the reflection electrode 19. Accordingly, the gap Da isalmost equal to the gap Db. Hence, the first incident light has abirefringence rate Δn×Da almost equal to a birefringence rate Δn×Db ofthe second incident light Lib, unlike the conventional liquid crystaldisplay device illustrated in FIG. 2 in which the incident light Lia hasa different birefringence rate from that of the incident light Lib. As aresult, the reflected light Lrb having been reflected at the drainwiring 16 shifts to being bluish from being yellowish, ensuring that awhite image displayed in a screen of the liquid crystal display deviceis prevented from being yellowish.

FIG. 6A shows a positional relation between the drain wiring 16 and thereflection electrode 19 in the liquid crystal display device 10.

In the liquid crystal display device 10, as illustrated in FIG. 6A, thereflection electrode 19 is formed on the electrically insulating film 18such that the reflection electrode 19 does not overlap the drain wiring16, that is, ends of the reflection electrode 19 are not located abovethe drain wiring 16. The ends of the reflection electrode 19 are spacedaway such that there is a gap between the ends of the reflectionelectrode 19 and ends of the drain wiring 16, when vertically viewed.

If the reflection electrode 19 overlaps the drain wiring 16, a parasiticcapacity defined by the reflection electrode 19 and the drain wiring 16would be increased, resulting in fluctuation in a pixel voltage. Incontrast, in accordance with the liquid crystal display device 10, it ispossible to prevent the parasitic capacity from increasing, ensuringprevention of fluctuation in a pixel electrode. Thus, the displaycharacteristic of the liquid crystal display device 10 is not harmfullyinfluenced, even when two drain wirings have the same voltage polarity,for instance, in so-called gate line inversion drive.

FIG. 6B shows another positional relation between the drain wiring 16and the reflection electrode 19 in the liquid crystal display device 10.

The reflection electrode 19 may be formed on the electrically insulatingfilm 18 such that the ends of the reflection electrode 19 are located inalignment with the opposite ends of the drain wiring 16, as illustratedin FIG. 6B. As illustrated, this defines an opening within reflectionelectrode 19 that is in vertical alignment with the first projection.

As an alternative, even if the reflection electrode 19 overlaps thedrain wiring 16 at one of the ends thereof, for instance, due tomisregistration of a mask for forming the reflection electrode 19, theabove-mentioned merit brought by the first embodiment can be obtained,if the reflection electrode 19 does not overlap the drain wiring 16 atthe other end.

FIGS. 7A to 7D are cross-sectional views of the liquid crystal displaydevice 10, showing steps to be carried out for fabricating the same.

First, as illustrated in FIG. 7A, the thin film transistor 15 and thedrain wiring 16 are formed on the first substrate 14.

Then, as illustrated in FIG. 7B, the first projection 17 a is formed onthe drain wiring 16, and the second projections 17 b are formed on thefirst substrate 14. For instance, the first and second projections 17 aand 17 b may be formed by coating organic resin over the first substrate14 on which the thin film transistor 15 and the drain wiring 16 havebeen already formed, applying a photoresist film over the resin,exposing the photoresist film to a light, developing the photoresistfilm to thereby form a mask, and etching the resin through the mask.

Then, as illustrated in FIG. 7C, the electrically insulating film 18composed of organic resin is formed so as to cover the first and secondprojections 17 a and 17 b, the thin film transistor 15, and the firstsubstrate 14 therewith. Then, the electrically insulating film 18 isformed with the contact hole 18 a by photolithography and etching. Thecontact hole 18 a reaches a source electrode of the thin film transistor15.

The electrically insulating film 18 is formed such that the compensationlayer comprised of the first projection 17 a and the electricallyinsulating film 18 is equal to or greater in height than a raisedportion of the wavy surface of the reflection electrode 19.

Then, a thin electrically conductive film such as an aluminum film isformed covering the reflection electrode 19 therewith and filling thecontact hole 18 a therewith.

Then, the reflection electrode 19 is formed by carrying outphotolithography and etching to the thin electrically conductive film.The reflection electrode 19 is formed so as not to overlap the drainwiring 16, as illustrated in FIG. 7D.

FIGS. 8A and 8B are cross-sectional views of the liquid crystal displaydevice 10, showing steps to be carried out for forming the reflectionelectrode 19.

First, as illustrated in FIG. 8A, a resist pattern 22 is formed on analuminum film 19 a. Then, the aluminum film 19 a is etched for such aperiod of time that the aluminum film 19 a is removed by a lengthgreater than a width of a hole 22 a, as illustrated in FIG. 8B. Thus,the reflection electrode 19 can be formed so as not to overlap the drainwiring 16.

FIGS. 9A and 9B are cross-sectional views of the liquid crystal displaydevice 10, showing another step to be carried out for forming thereflection electrode 19.

As illustrated in FIG. 9A, a resist pattern 22 is formed on an aluminumfilm 19 a. The resist pattern 22 is formed with a hole 22 a having awidth equal to a length of the drain wiring 16 and located just inalignment with the drain wiring 16. By etching the aluminum film 19 athrough the resist pattern 22, the reflection electrode 19 can be formedsuch that the reflection electrode 19 does not overlap the drain wiring16, as illustrated in FIG. 9B.

The resist pattern 22 may be developed for such a long time that thereflection electrode 19 does not overlap the drain wiring 16, asillustrated in FIG. 9B.

As mentioned above, the compensation layer comprised of the firstprojection 17 a and the electrically insulating film 18 has a heightequal to or greater than a height of a raised portion of the wavysurface of the reflection electrode 19. The compensation layer is formedas follows.

FIGS. 10A and 10B show a relation between a width of a mask pattern anda width of the first or second projection 17 a or 17 b.

As shown in FIG. 10A, if a mask pattern had a width of 4.m, the first orsecond projection 17 a or 17 b would have a width of about 7.m and aheight of about 2.2. m, and, as shown in FIG. 10B, if a mask pattern hada width of 10.m, the first or second projection 17 a or 17 b would havea width of about 13.m and a height of about 2.8.m.

That is, greater a width of a mask pattern is, greater a height of thefirst or second projection 17 a or 17 b is. Hence, the first projection17 a could have a height greater than a height of the second projections17 b by designing a mask pattern for forming the first projection 17 ato have a width greater than a width of a mask pattern for forming thesecond projections 17 b.

When the first and second projections 17 a and 17 b are to be composedof acrylic resin, the first projection 17 a can be designed to have aheight equal to or greater than a height of the second projections 17 bin the same way as mentioned above.

Wider a line width of a photoresist pattern is, greater a height of aprojection composed of acrylic resin is. By utilizing this phenomenon,the first projection 17 a could be designed to have a width and a heightgreater than a width and a height of the second projections 17 b.

As mentioned above, the liquid crystal display device 10 in accordancewith the first embodiment has such a structure that the electricallyinsulating film 18 having a rounded summit is formed above the drainwiring 16, that the reflection electrode 19 does not overlap the drainwiring 16, and that the first projection 17 a is higher than the secondprojections 17 b.

That is, in the liquid crystal display device 10 in accordance with thefirst embodiment, the first projection 17 a and the electricallyinsulating film 18 are formed on the drain wiring 16 in order touniformize an average thickness of the liquid crystal layer 12, and theelectrically insulating film 18 is formed above the drain wiring 16 suchthat the reflection electrode 19 does not overlap the drain wiring 16.

Thus, the electrically insulating layer 18 constituting the compensationlayer formed above the drain wiring 16 is formed to have almost the sameheight as a height of the reflection electrode 19.

In the liquid crystal display device 10, the first projection 17 a andthe electrically insulating film 18 covering the first projection 17 apartially form the wavy surface of the reflection electrode 19, thereflection electrode 19 is formed not to overlap the drain wiring 16,and the electrically insulating film 18 formed above the drain wiring 16is designed to have almost the same height as a height of the reflectionelectrode 19.

As a result, as mentioned earlier, it is possible to prevent thereflected light Lrb from being yellowish, and further possible toprevent a white image displayed in a display screen of the liquidcrystal display device 10, from being yellowish.

In accordance with the liquid crystal display device 10, it is possibleto prevent the parasitic capacity from increasing, ensuring preventionof fluctuation in a pixel electrode. Thus, the display characteristic ofthe liquid crystal display device 10 is not harmfully influenced, evenwhen two drain wirings have the same voltage polarity, for instance, inthe gate line inversion drive.

In the above-mentioned embodiment, though the thin film transistor 15 isused as a switching device, a diode or other switching devices may beused in place of the thin film transistor 15.

In the above-mentioned embodiment, the first projection 17 a and theelectrically insulating film 18 are formed above the drain wiring 16 inorder to equalize the gaps Da and Db (see FIG. 5) to each other.However, the first projection 17 a and the electrically insulating film18 may be formed above another wiring layer to do so.

While the present invention has been described in connection withcertain preferred embodiments, it is to be understood that the subjectmatter encompassed by way of the present invention is not to be limitedto those specific embodiments. On the contrary, it is intended for thesubject matter of the invention to include all alternatives,modifications and equivalents as can be included within the spirit andscope of the following claims.

The entire disclosure of Japanese Patent Application No. 2000-343714filed on Nov. 10, 2000 including specification, claims, drawings andsummary is incorporated herein by reference in its entirety.

1. A method of fabricating a liquid crystal display device including a first substrate; a second substrate spaced away from and facing said first substrate; a liquid crystal layer sandwiched between said first and second substrates; and a reflection electrode formed on said first substrate, an external incident light being reflected at said reflection electrode towards a viewer, said method comprising the steps of: (a) forming a switching device and a wiring layer on said first substrate, said wiring layer being electrically connected to said switching device, (b) forming a first projection on said wiring layer and second projections on said first substrate; (c) covering said first and second projections with an electrically insulating layer; (d) forming an electrically conductive film over said electrically insulating layer; and (e) patterning said electrically conductive film such that said electrically conductive film does not overlap said wiring layer and said patterned film forms a reflection electrode having an opening in vertical alignment with the first projection, wherein said electrically conductive film is formed to have ends located above and in alignment with opposite ends of said wiring layer.
 2. The method as set forth in claim 1, wherein said first projection and said electrically insulating layer are formed to have almost the same combined height as a combined height of said second projections, said electrically insulating layer and said electrically conductive film.
 3. The method as set forth in claim 1, wherein said electrically insulating layer is formed to have a wavy surface, and said electrically conductive film is formed to have a surface reflecting said wavy surface of said electrically insulating layer.
 4. The method as set forth in claim 1, wherein said first projection defines a rectangular frame, and said second projections define a plurality of linear projections each extending in different directions from one another within said rectangular frame.
 5. The method as set forth in claim 4, wherein said first projection is formed to have a greater width than a width of said linear projections.
 6. The method as set forth in claim 1, wherein said first projection has a height almost the same as a combined height of said second projections and said electrically insulating layer.
 7. A method of fabricating a liquid crystal display device including a first substrate; a second substrate spaced away from and facing said first substrate; a liquid crystal layer sandwiched between said first and second substrates; and a reflection electrode formed on said first substrate an external incident light being reflected at said reflection electrode towards a viewer, said method comprising the steps of: (a) forming a switching device and a wiring layer on said first substrate, said wiring layer being electrically connected to said switching device, (b) forming a first projection on said wiring layer and second projections on said first substrate; (c) covering said first and second projections with an electrically insulating layer; (d) forming an electrically conductive film over said electrically insulating layer; and (e) patterning said electrically conductive film such that said electrically conductive film does not overlap said wiring layer and said patterned film forms a reflection electrode having an opening in vertical alignment with the first projection, wherein said step (e) includes the steps of: (e1) forming a photoresist layer over said electrically conductive film; (e2) forming a hole throughout said photoresist layer above said wiring layer, said hole reaching said electrically conductive film; and (e3) etching said electrically conductive film such that an etched portion of said electrically conductive film has a length greater than a width of said hole, said etched portion forming the opening.
 8. A method of fabricating a liquid crystal display device including a first substrate; a second substrate spaced away from and facing said first substrate; a liquid crystal layer sandwiched between said first and second substrates; and a reflection electrode formed on said first substrate, an external incident light being reflected at said reflection electrode towards a viewer, said method comprising the steps of: (a) forming a switching device and a wiring layer on said first substrate, said wiring layer being electrically connected to said switching device, (b) forming a first projection on said wiring layer and second projections on said first substrate; (c) covering said first and second projections with an electrically insulating layer; (d) forming an electrically conductive film over said electrically insulating layer; and (e) patterning said electrically conductive film such that said electrically conductive film does not overlap said wiring layer, wherein said first projection defines a rectangular frame, and said second projections define a plurality of linear projections each extending in different directions from one another within said rectangular frame, wherein said electrically conductive film is formed to have ends located above and in alignment with opposite ends of said wiring layer.
 9. A method of fabricating a liquid crystal display device including a first substrate; a second substrate spaced away from and facing said first substrate; a liquid crystal layer sandwiched between said first and second substrates; and a reflection electrode formed on said first substrate, an external incident light being reflected at said reflection electrode towards a viewer, said method comprising the steps of: (a) forming a switching device and a wiring layer on said first substrate, said wiring layer being electrically connected to said switching device, (b) forming a first projection on said wiring layer and forming second projections on said first substrate; (c) covering said first and second projections with an electrically insulating layer; (d) forming an electrically conductive film over said electrically insulating layer; and (e) patterning said electrically conductive film such that said electrically conductive film has ends in alignment above opposite ends of said wiring layer to form a reflection electrode with an opening in vertical alignment with the first projection.
 10. The method as set forth in claim 9, wherein said step (e) includes the steps of: (e1) forming a photoresist layer over said electrically conductive film; (e2) forming a hole throughout said photoresist layer above said wiring layer, said hole reaching said electrically conductive film; and (e3) etching said electrically conductive film such that an etched portion of said electrically conductive film has a length greater than a width of said hole, said etched portion forming the opening.
 11. The method as set forth in claim 9, wherein said first projection and said electrically insulating layer are formed to have the same combined height as a combined height of said second projections, said electrically insulating layer and said electrically conductive film.
 12. The method as set forth in claim 9, wherein said electrically insulating layer is formed to have a wavy surface, and said electrically conductive film is formed to have a surface reflecting said wavy surface of said electrically insulating layer.
 13. The method as set forth in claim 9, wherein the ends of said electrically conductive film are located above in vertical alignment with the opposite ends of said wiring layer.
 14. The method as set forth in claim 9, wherein said first projection defines a rectangular frame, and said second projections define a plurality of linear projections each extending in different directions from one another within said rectangular frame.
 15. The method as set forth in claim 14, wherein said first projection is formed to have a greater width than a width of said linear projections.
 16. The method as set forth in claim 9, wherein said first projection has a height the same as a combined height of said second projections and said electrically insulating layer. 